Drive unit



April 22,-' 1947. j M. DONIAK 2,419,392

DRIVE NIT` Y Filed Dec. fr, 1945 l mllll vrolls to remove thecorrugations.

Patented Apr. 22, 1947 UNITED STATES PATENT OFFICE DRIVE UNIT MichaelDoniak, Lynwood, Calif.

Application December 7, 1943, Serial No. 513,221

2 Claims. 1

My invention relates to a drive unit and has particular reference to animproved type of drive unit which finds particular utility when employedas the final drive unit in such mechanisms as paper making machines andthe like.

In the conventional paper mill drive the relative arrangement of partsis such that the interconnection between an adjustable speed jack shaftand the drive for the main rolls must be effected by a iinal drive unitwhich provides a gear reduction in the order of six to one and whichprovides also a 90 change in the direction of the drive. In theconventional arrangements this is accomplished by providing on thevariable speed jack shaft a bevel pinion which meshes with a bevel ringgear mounted on the drive shaft for the main rolls. The drive ratioemployed is usually about six to one which is eifected by using afourteen tooth bevel pinion meshing with an eighty-four tooth bevel ringgear.

Because of the high rotational speed of the bevel pinion as comparedwith the bevel ring gear and because of the six to one ratio indiameters between these two gears, the arrangement just described issusceptible to very rapid wear of the :bevel pinion. This wear shortlyintroduces considerable vibration during the operation of the machine.This vibration is highly objectionable because it imposes undue stressesupon other parts of the machine and thus hastens the wearing out of suchparts. What is more important, the vibration is transmitted to therubber covered main drive rolls with the result that there is producedin this rubber covering a series of corrugations, making it necessary tofrequently reg-rind these Since only a limited number of regrindingoperations may be performed, it is often necessary to replace the rollafter a relatively short useful life. In addition, the rapid Wearing outof the bevel pinion results in the ultimate failure of the pinionrequiring its replacement.

Each of the disadvantages mentioned above result in considerable loss oftime, both because of the time required to make the repairs orreplacements and because of the time lost in getting the machine backinto smooth and satisfactory operation, a process which often requiresthe eX- ypenditure of considerable time in the making of adjustments inthe speed of the machine and in 2 the rate at which the pulp or othermaterial is supplied to the machine.

It is, therefore, an object of my invention to provide an improved driveunit which may be used in place of the final drive referred to in the'preceding paragraphs and which overcomes the disadvantages above notedby employing a double reduction unit of novel arrangement. l

It is also an object of my inventionto provide a drive unit of thecharacter referred to in the preceding paragraph in which the functionsof gear reduction and direction change are performed by separate partsof the unit, and in which the desired gear ratio is obtained by a doublereduction unit.

It is an additional object of my invention to provide a drive unit ofthe character previously referred to in which the direction changingunit is provided with a drive ratio of unity and positioned between thetwo parts of the double reduction unit.

It is a still further object of my invention to provide a drive unit ofthe character referred to in the preceding paragraphs in which the twoparts of the double reduction unit provide approximately equal driveratios, each substantially equal to the square root of the desiredoverall drive ratio.

It is additionally an object o-f my invention to provide a drive unit ofthe character referred to hereinbefore in which the parts are compaotlyarranged to occupy but little more space than the conventional driveunit which it replaces.

Other objects and advantages of my invention will be :apparent from astudy of the following specifications, read in connection with theaccompanying drawings, wherein:

Fig. 1 is a schematic representation of one form of drive system, therehaving been selected for illustration in Fig. 1 the driving systememployed for paper making machines; and

Fig. 2 is a sectional view illustrating the preferred embodiment of theimproved drive unit of my invention adapted for use with a drivingsystem such as that represented in Fig. 1.

Referring to the drawings, I have chosen for illustration in Fig. 1 thedrivingl arrangement of a paper making machine as a typical form ofdriving system with which the drive unit of my invention is particularlyadapted to use. This respective shafts.

driving system derives its power from a suitable power source shown inFig. 1 as comprising an electric motor I. The electric motor I isdrivably connected, as by means of a belt and pulley ari rangement 2, toa line shaft 3. The line shaft 3 is connected to a variable speed jackshaft 4 by a variable radio transmission illustrated in Fig. l ascomprising cone pulleys 5 and 6 mounted on the shafts 3 and ll,respectively, and interconnected as by means of a belt 'I.

The jack shaft li is connected through the medium of a nal drive unitindicated generally by the reference character 8 to a shaft 9 whichcomprises the drive shaft for the main rolls of the paper makingmachine. In the conventional arrangements the shaft i and the shaft 9are disposed at ri-ght angles to each other and the requirements of themachine are such as to employ within the drive unit 9 a gear reductionof approximately six to one between the shafts 4 and 9. As has beenhereinbefore indicated, in

the conventional constructions this is accom plished by means of a bevelpinion mounted on the shaft 4 meshing with a large bevel ring gearmounted on the shaft 9.

I have illustrated in Fig. 2 an improved drive unit which, bypreference, is used as the drive unit 8 above referred to. As is shownin Fig. 2, the drive unit 8 may include a suitable housing I9 withinwhich one end of the shaft l may be journaled as by means of a journal lI and within which may also be journaled one end of the shaft 9 as bymeans of a journal I2.

Within the housing IE! there are mounted two countershafts I3 and I4,the former being disposed parallel to the shaft Il and the latter beingdisposed parallel to the shaft 9, both the shafts I3 and I4 beingsuitably journaled for rotation as by means of bearings or journals I5,IES, II and I8,

The shaft I3 is drivably connected to the shaft 4 by means of alrstspeed reduction unit I9 illustrated in Fig. 2 as comprising a chainand sprocket drive employing a small diameter sprocket 29 secured to theshaft d and a large diameter sprocket 2i secured to the shaft I3, thesprockets 20 and 2! being drivably interconnected by means of a chain orlink belt 22.

The shaft I3 is arranged to drive the shaft I4 at an equal speed bymeans of intermeshing bevel or miter gears 23 and 24 mounted upon theare of the same size so as to provide a drive ratio of unity between theshafts I3 and I4.

The shaft I4 is likewise drivably engaged with the shaft 9 by means of asecond speed reduction unit 25 illustrated in Fig. 2 as comprising achain and sprocket unit including a small diameter sprocket 26 mountedupon the shaft I4 and a large diameter sprocket 27 mounted upon theshaft 9, the sprockets 29 and 27 being drivably interconnected by meansof a chain or link belt 28. For example, roller chain may be used, inwhich event no pre-tensioning of the chain is required.

It will be noted that with the arrangement above described the requiredchange cf direction is effected by the miter gears 23 and 2d, whereasthe speed reduction between the shafts 4 and 9 is effected by the doublereduction drive unit comprising the speed reduction portions I9 and 25.While I have shown these speed reduction units as comprising, bypreference, chain and sprocket drives, it will be appreciated that undercircumstances indicating the desirability of such an alternativearrangement, a direct geared connec- By reference these bevel gears tionbetween the respective shafts or pulleys and belts may be used, ifdesired.

As has been hereinbefore stated, the conventional drive unit provides agear reduction of six to one between the shafts 4 and 9. This samereduction may be obtained with the improved unit just described bymaking the drive ratio of the parts I9 and 25 approximately equal to thesquare root of six. For example, one convenient arrangement consists inproviding one of the drive units with a drive ratio of 2.67 to one andthe other unit with a ratio 2.25 to one. Such drive ratios may berealized by providing twelve teeth on each of the sprockets 29 and 2Sand by providing twenty-seven and thirty-two teeth, respectively, on thetwo larger sprockets.

Attention is directed to the fact that in the arrangement described, thetotal required speed reduction between the shafts 4 and 9 isaccomplished by using a double reduction unit, and particular attentionis directed to the fact that the required direction change isaccomplished by using miter gears having a drive ratio of unity and thatthese miter gears are interposed between the two parts of the doublereduction unit.

I have found that with this arrangement a very substantial increase inthev operating life of the drive unit as a whole may be readilyrealized. The provision of two speed reducers instead of the usualsingle speed reducer diminishes to onehalf the forces imposed on each ofthe speed reducer components, such as sprocket teeth, chain rollers,etc., reducing the wear of these parts. Furthermore, because the forcesimposed on each of the component parts of the speed reducers are muchmore nearly equal than in the conventional drive system, the parts tendto wear more equally, with the result that the rate at which the partswear is greatly reduced and the development of undesired vibrations ofthe shaft 9 is practically prevented.

Also, by effecting the change in drive direction by miter gears having aone to one ratio, the loads imposed on each of the elements of this partof the system are made equal so that any wear involved is equallydivided, thus reducing to a minimum any difference in the rate at whicheach part wears.

I have found through actual use that a system of the type describedpermits a material increase in the length of time a paper making machinemay be operated without requiring adjustments or repairs.

While I have shown and described the preferred embodiment of myinvention, I do not desire to be limited to any of the details ofconstruction shown or described herein, except as dened in the appendedclaims.

I claim:

l. In a drive mechanism for driving rolls of paper mills for obtaining aspeed reduction between a drive shaft and a driven shaft extending atright angles to said drive shaft, the combination of a drive shaft; ajack shaft disposed parallel to said drive shaft; a chain and sprocketspeed reducing drive connecting said jack shaft to said drive shaft; adriven shaft; another jack shaft disposed parallel to-said driven shaft;.another chain and sprocket speed reducing drive connecting said otherjack shaft to said driven shaft; and coupling means drivablyinterconnecting said jack shafts and comprising intermeshing miter gearsof equal diameters.

2. In a drive mechanism for driving rolls of paper mills for obtaining adesired speed reduction of about siX to one between a drive shaft and adriven shaft extending at right angles to said drive shaft, thecombination of: a drive shaft; a jack shaft disposed parallel to saiddrive shaft; a chain and sprocket speed reducing drive connecting saidjack shaft to said drive shaft; a driven shaft; another jack shaftdisposed parallel to said driven shaft; another chain and sprocket speedreducing drive connecting said other jack shaft tov said driven shaft;and couplin-grmeans drivably interconnecting said jack shafts andcomprising intermeshing miter gears of equal diameters, said chain andsprocket drives each having drive ratios approximately equal to thesquare root of said desired speed reduction.

MICHAEL DONIAK.

` 6 REFERENCES CITED The following references are of record in the 111eof this patent:

UNITED STATES PATENTS Number Name Date 849,100 Balandras Aug. 7, 19392,248,792 Taylor July 8, 1941 964,802 Moo-n et al July 19, 1910 102,028,282 Hoe Jan. 21, 1936 2,337,586 Bowen Dec, 28, 1943 1,082,349Likness Dec. 23, 1913 FOREIGN PATENTS Number Country Date 23,974 BritishOct. 21, 1912

